diff options
Diffstat (limited to 'meta-openbmc-mods/meta-ast2500/recipes-bsp/u-boot/files/0054-U-Boot-4-4-lib-uuid-Improve-randomness-of-uuid-values-on-RANDOM_UUID-y.patch')
| -rw-r--r-- | meta-openbmc-mods/meta-ast2500/recipes-bsp/u-boot/files/0054-U-Boot-4-4-lib-uuid-Improve-randomness-of-uuid-values-on-RANDOM_UUID-y.patch | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/meta-openbmc-mods/meta-ast2500/recipes-bsp/u-boot/files/0054-U-Boot-4-4-lib-uuid-Improve-randomness-of-uuid-values-on-RANDOM_UUID-y.patch b/meta-openbmc-mods/meta-ast2500/recipes-bsp/u-boot/files/0054-U-Boot-4-4-lib-uuid-Improve-randomness-of-uuid-values-on-RANDOM_UUID-y.patch new file mode 100644 index 000000000..2e960ae58 --- /dev/null +++ b/meta-openbmc-mods/meta-ast2500/recipes-bsp/u-boot/files/0054-U-Boot-4-4-lib-uuid-Improve-randomness-of-uuid-values-on-RANDOM_UUID-y.patch @@ -0,0 +1,160 @@ +From patchwork Tue Apr 30 02:53:47 2019 +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: 7bit +X-Patchwork-Submitter: Eugeniu Rosca <erosca@de.adit-jv.com> +X-Patchwork-Id: 1092945 +X-Patchwork-Delegate: xypron.glpk@gmx.de +Return-Path: <u-boot-bounces@lists.denx.de> +X-Original-To: incoming@patchwork.ozlabs.org +Delivered-To: patchwork-incoming@bilbo.ozlabs.org +Authentication-Results: ozlabs.org; + spf=none (mailfrom) smtp.mailfrom=lists.denx.de + (client-ip=81.169.180.215; helo=lists.denx.de; + envelope-from=u-boot-bounces@lists.denx.de; + receiver=<UNKNOWN>) +Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) + header.from=de.adit-jv.com +Received: from lists.denx.de (dione.denx.de [81.169.180.215]) + by ozlabs.org (Postfix) with ESMTP id 44tR5425wgz9s9N + for <incoming@patchwork.ozlabs.org>; + Tue, 30 Apr 2019 12:56:56 +1000 (AEST) +Received: by lists.denx.de (Postfix, from userid 105) + id 0D1ECC21E13; Tue, 30 Apr 2019 02:55:52 +0000 (UTC) +X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lists.denx.de +X-Spam-Level: +X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=unavailable + autolearn_force=no version=3.4.0 +Received: from lists.denx.de (localhost [IPv6:::1]) + by lists.denx.de (Postfix) with ESMTP id C6B77C21DFB; + Tue, 30 Apr 2019 02:55:49 +0000 (UTC) +Received: by lists.denx.de (Postfix, from userid 105) + id 8E8ADC21DFA; Tue, 30 Apr 2019 02:55:25 +0000 (UTC) +Received: from smtp1.de.adit-jv.com (smtp1.de.adit-jv.com [93.241.18.167]) + by lists.denx.de (Postfix) with ESMTPS id A4EF5C21DA1 + for <u-boot@lists.denx.de>; Tue, 30 Apr 2019 02:55:24 +0000 (UTC) +Received: from localhost (smtp1.de.adit-jv.com [127.0.0.1]) + by smtp1.de.adit-jv.com (Postfix) with ESMTP id 838C73C013A; + Tue, 30 Apr 2019 04:55:24 +0200 (CEST) +Received: from smtp1.de.adit-jv.com ([127.0.0.1]) + by localhost (smtp1.de.adit-jv.com [127.0.0.1]) (amavisd-new, + port 10024) + with ESMTP id ek0voy46TSnZ; Tue, 30 Apr 2019 04:55:17 +0200 (CEST) +Received: from HI2EXCH01.adit-jv.com (hi2exch01.adit-jv.com [10.72.92.24]) + (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) + (No client certificate requested) + by smtp1.de.adit-jv.com (Postfix) with ESMTPS id D04A33C00DD; + Tue, 30 Apr 2019 04:55:17 +0200 (CEST) +Received: from vmlxhi-102.adit-jv.com (10.72.93.184) by HI2EXCH01.adit-jv.com + (10.72.92.24) with Microsoft SMTP Server (TLS) id 14.3.439.0; + Tue, 30 Apr 2019 04:55:17 +0200 +From: Eugeniu Rosca <erosca@de.adit-jv.com> +To: Lukasz Majewski <lukma@denx.de>, Heinrich Schuchardt <xypron.glpk@gmx.de>, + Simon Glass <sjg@chromium.org>, Marek Vasut <marek.vasut@gmail.com>, + Stephen Warren <swarren@nvidia.com>, Roman Stratiienko + <roman.stratiienko@globallogic.com>, <u-boot@lists.denx.de> +Date: Tue, 30 Apr 2019 04:53:47 +0200 +Message-ID: <20190430025347.3097-5-erosca@de.adit-jv.com> +X-Mailer: git-send-email 2.21.0 +In-Reply-To: <20190430025347.3097-1-erosca@de.adit-jv.com> +References: <20190430025347.3097-1-erosca@de.adit-jv.com> +MIME-Version: 1.0 +X-Originating-IP: [10.72.93.184] +Cc: Eugeniu Rosca <erosca@de.adit-jv.com>, + Eugeniu Rosca <roscaeugeniu@gmail.com> +Subject: [U-Boot] [PATCH 4/4] lib: uuid: Improve randomness of uuid values + on RANDOM_UUID=y +X-BeenThere: u-boot@lists.denx.de +X-Mailman-Version: 2.1.18 +Precedence: list +List-Id: U-Boot discussion <u-boot.lists.denx.de> +List-Unsubscribe: <https://lists.denx.de/options/u-boot>, + <mailto:u-boot-request@lists.denx.de?subject=unsubscribe> +List-Archive: <http://lists.denx.de/pipermail/u-boot/> +List-Post: <mailto:u-boot@lists.denx.de> +List-Help: <mailto:u-boot-request@lists.denx.de?subject=help> +List-Subscribe: <https://lists.denx.de/listinfo/u-boot>, + <mailto:u-boot-request@lists.denx.de?subject=subscribe> +Errors-To: u-boot-bounces@lists.denx.de +Sender: "U-Boot" <u-boot-bounces@lists.denx.de> + +The random uuid values (enabled via CONFIG_RANDOM_UUID=y) on our +platform are always the same. Below is consistent on each cold boot: + + => ### interrupt autoboot + => env default -a; gpt write mmc 1 $partitions; print uuid_gpt_misc + ... + uuid_gpt_misc=d117f98e-6f2c-d04b-a5b2-331a19f91cb2 + => env default -a; gpt write mmc 1 $partitions; print uuid_gpt_misc + ... + uuid_gpt_misc=ad5ec4b6-2d9f-8544-9417-fe3bd1c9b1b3 + => env default -a; gpt write mmc 1 $partitions; print uuid_gpt_misc + ... + uuid_gpt_misc=cceb0b18-39cb-d547-9db7-03b405fa77d4 + => env default -a; gpt write mmc 1 $partitions; print uuid_gpt_misc + ... + uuid_gpt_misc=d4981a2b-0478-544e-9607-7fd3c651068d + => env default -a; gpt write mmc 1 $partitions; print uuid_gpt_misc + ... + uuid_gpt_misc=6d6c9a36-e919-264d-a9ee-bd00379686c7 + +While the uuids do change on every 'gpt write' command, the values +appear to be taken from the same pool, in the same order. + +As a user, I expect a trully random uuid value in the above example. +Otherwise, system/RFS designers and OS people might assume they have +a reliable/consistent uuid passed by the bootloader, while the truth +is U-Boot simply lacks entropy to generate a random string. + +In its first attempt [1] to improve the uuid randomness, this patch +updated the seed based on the output of get_timer(), similar to [2]. + +There are two problems with this approach: + - get_timer() has a poor _ms_ resolution + - when gen_rand_uuid() is called in a loop, get_timer() returns the + same result, leading to the same seed being passed to srand(), + leading to the same uuid being generated for several partitions + with different names + +This second patch addresses both drawbacks. + +My R-Car3 testing [3] consists of running 'gpt write mmc 1 $partitions' +in a loop for several minutes collecting 8844 randomly generated UUIDS. +Two consecutive cold boots are concatenated in the log. As a result, +all uuid values are unique (scripted check). + +Thanks to Roman, who reported the issue and provided support in fixing. + +[1] https://patchwork.ozlabs.org/patch/1091802/ +[2] commit da384a9d7628 ("net: rename and refactor eth_rand_ethaddr() function") +[3] https://gist.github.com/erosca/2820be9d554f76b982edd48474d0e7ca + => while true; do \ + env default -a; \ + gpt write mmc 1 $partitions; \ + print; done + +Reported-by: Roman Stratiienko <roman.stratiienko@globallogic.com> +Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> +--- +v2: + - Replaced get_timer(0) with get_ticks() and added rand() to seed value + - Performed extensive testing on R-Car3 (ARMv8) +v1: + - https://patchwork.ozlabs.org/patch/1091802/ +--- + lib/uuid.c | 2 ++ + 1 file changed, 2 insertions(+) + +diff --git a/lib/uuid.c b/lib/uuid.c +index fa20ee39fc32..2d4d6ef7e461 100644 +--- a/lib/uuid.c ++++ b/lib/uuid.c +@@ -238,6 +238,8 @@ void gen_rand_uuid(unsigned char *uuid_bin) + unsigned int *ptr = (unsigned int *)&uuid; + int i; + ++ srand(get_ticks() + rand()); ++ + /* Set all fields randomly */ + for (i = 0; i < sizeof(struct uuid) / sizeof(*ptr); i++) + *(ptr + i) = cpu_to_be32(rand()); |